Gold nanoparticles-based catalysis for detection of S-nitrosothiols in blood serum

Analytical Methods for Assessing Thiol Antioxidants in Biological Fluids: A Review

Redox metabolism is an integral part of the glutathione system, encompassing reduced and oxidized glutathione, hydrogen peroxide, and associated enzymes. This core process orchestrates a network of thiol antioxidants like thioredoxins and peroxiredoxins, alongside critical thiol-containing proteins such as mercaptoalbumin. Modifications to thiol-containing proteins, including oxidation and glutathionylation, regulate cellular signaling influencing gene activities in inflammation and carcinogenesis. Analyzing thiol antioxidants, especially glutathione, in biological fluids offers insights into pathological conditions. This review discusses the analytical methods for biothiol determination, mainly in blood plasma. The study includes all key methodological aspects of spectroscopy, chromatography, electrochemistry, and mass spectrometry, highlighting their principles, benefits, limitations, and recent advancements that were not included in previously published reviews. Sample preparation and factors affecting thiol antioxidant measurements are discussed. The review reveals that the choice of analytical procedures should be based on the specific requirements of the research. Spectrophotometric methods are simple and cost-effective but may need more specificity. Chromatographic techniques have excellent separation capabilities but require longer analysis times. Electrochemical methods enable real-time monitoring but have disadvantages such as interference. Mass spectrometry-based approaches have high sensitivity and selectivity but require sophisticated instrumentation. Combining multiple techniques can provide comprehensive information on thiol antioxidant levels in biological fluids, enabling clearer insights into their roles in health and disease. This review covers the time span from 2010 to mid-2024, and the data were obtained from the SciFinder® (ACS), Google Scholar (Google), PubMed®, and ScienceDirect (Scopus) databases through a combination search approach using keywords.

Transient Vasodilation in Mouse 4T1 Tumors after Intragastric and Intravenous Administration of Gold Nanoparticles

Gold nanoparticles (AuNPs) are foreseen as a promising tool in nanomedicine, both as drug carriers and radiosensitizers. They have been also proposed as a potential anticancer drug due to the anti-angiogenic effect in tumor tissue. In this work we investigated the effect of citrate-coated AuNPs of nominal diameter 20 nm on the growth and metastatic potential of 4T1 cells originated from a mouse mammary gland tumor inoculated into the mammary fat pad of Balb/ccmdb mice. To evaluate whether AuNPs can prevent the tumor growth, one group of inoculated mice was intragastrically (i.g.) administered with 1 mg/kg of AuNPs daily from day 1 to day 14 after cancer cell implantation. To evaluate whether AuNPs can attenuate the tumor growth, the second group was intravenously (i.v.) administered with 1 or 5 mg/kg of AuNPs, twice on day 5 and day 14 after inoculation. We did not observe any anticancer activity of i.v. nor i.g. administered AuNPs, as they did not affect neither the primary tumor growth rate nor the number of lung metastases. Unexpectedly, both AuNP treatment regimens caused a marked vasodilating effect in the tumor tissue. As no change of potential angiogenic genes (Fgf2, Vegfa) nor inducible nitric oxygenase (Nos2) was observed, we proposed that the vasodilation was caused by AuNP-dependent decomposition of nitrosothiols and direct release of nitric oxide in the tumor tissue.

Light triggering goldsomes enable local NO-generation and alleviate pathological vasoconstriction

While nitric oxide (NO) can remedy vasoconstriction, inhalation of NO may cause systematic toxicity. We report a goldsome, which comprises a hollowed poly(lactic-co-glycolic acid) (PLGA) polymersome with S-nitrosoglutathione (GSNO, a NO donor) molecules and gold nanoparticles (Au NPs) incorporated in its hydrophilic core and hydrophobic membrane, respectively. Photothermal heating caused breakdown of polymersomes and enabled NO generation through reaction between GSNO and Au NPs. Photo-illumination at the zebrafish head led to local NO generation and selective cerebral vasodilation while it had little effects in regions away from the illumination site, and effectively mitigated hypoxia induced cerebral vasoconstriction. We demonstrate a translational potential by showing photo-stimulated NO generation with a clinical intravascular optical catheter. In conclusion, the goldsome, which enables light stimulated local NO generation and can be delivered with clinical intravascular optical catheters, should extend applications of NO therapies while surmounting limitations associated with systemic administration.

Pitfalls of assays devoted to evaluation of oxidative stress induced by inorganic nanoparticles

During the last years, there has been a remarkable increase in the use of inorganic nanoparticles (NP) in different applications, including consumer and medical products. Despite these promising applications, the extremely small size of NP allows them to penetrate cells, in which they can interact with intracellular structures causing serious side effects. A number of studies showed that NP cause adverse effects predominantly via induction of an oxidative stress - an imbalance between damaging oxidants and protective antioxidants - resulting in inflammation, immune response, cell damages, genotoxicity, etc … Most of the in vitro methods used for measurement of oxidative stress biomarkers were designed and standardized for conventional organic, inorganic and biochemical compounds. More recently, these methods have been adapted to studies related to various nanomaterials. Thus, this review is an attempt to highlight some current methods employed in and to provide a critical analysis of the major challenges and issues faced in this emerging field.